Questions tagged [pcb-fabrication]

About the manufacturing of PCBs (Printed Circuit Boards).

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58
votes
6answers
31k views

What is Copper Thieving and why use it?

On many boards I've seen, there are little copper dots used for the purpose of "Copper Thieving". They're small round copper dots connected to nothing and arranged in an array. Supposedly they're for ...
111
votes
8answers
36k views

Best One-Off DIY PCB Creation Technique

I have finally built up a lab to design electronics in. I have quite a few designs I would like to test. I have tried the printer toner/iron technique a few times but have found that I cannot create ...
36
votes
8answers
6k views

How to prototype?

How is prototyping done in a professional EE environment? Do you do your prototypes on breadboards, on copper clad boards, Manhattan style, or do you just draw schematics, order PCBs made and ...
8
votes
4answers
8k views

Are acid traps real? (2014)

Some people online say that acute angles in trace routing will cause these problems: "Acid Trap" - PCB etchant gets stuck in the corner, and eats away too much, causing open circuit "Peelable" - ...
57
votes
16answers
73k views

How do you cut PCB?

I just spent about 20 minutes trying to cut through a PCB with a hacksaw. These things are really tough. What is the correct tool to cut PCB material, and get a nice straight line? I saw something ...
15
votes
5answers
6k views

Anything bad to place a via on a pad?

Once I mistakenly placed a via on 0603 pad and didn't have any problem on soldering. I am routing another board now and I could save some space by placing some vias (0.3mm) on a 0603 pad. I wonder if ...
9
votes
2answers
4k views

Air gap on isolation space

The below photo belongs to a PSU. I wonder what was the reason of placing air gaps on the 8 mm isolation. Is it to improve the isolation or provide a thermal relief (although there is no component ...
6
votes
3answers
19k views

What is a suitable temperature rise for PCB traces?

I'm designing a PCB for a 10A relay and am trying to determine what the trace width should be. According to this trace width calculator, the biggest factors in the width are copper thickness, ...
5
votes
3answers
3k views

Is there a standard PCB Array Size for PCB Assembly?

I am planning on use various PCB assembly houses to get my boards PCB assembled. To minimize process costs, I am told it is best to panelize/array the PCB such that there is multiple boards per array, ...
4
votes
3answers
3k views

PCB opaque coating for anti reverse engineering?

Im trying to find a coating for my PCB in order to protect it from reverse engineering. I want it opaque, non-conductive and with a low thermal resistance. Basically I do not want that someone ...
2
votes
3answers
839 views

What is the best way to plate VIAs?

My local hackerspace has a CNC machine. I can give them my Gerbers and they can print out the PCB. The machine does not plate VIAs. I need to do this after the CNC machine is finished. What is the ...
0
votes
2answers
174 views

Use spray paint to make mask for pre-sensitised board?

I'm about to etch my first simple board for a project. I have a pre-sensitised board that (as I understand the process) you expose to UV light, then develop the board in a sodium hydroxide solution, ...
18
votes
13answers
5k views

Recommended PCB houses / Assemblers [closed]

Can anyone recommend a good place to go making PCB's? I'm particularly interested in places that also offer assembly, because this makes SMD parts an option. GoldPhoenix is an option, but not the ...
11
votes
12answers
9k views

Moderately priced 6-layer PCB fab?

I have a board I'm working on with a coworker; we are debating whether to go 4-layer or 6-layer board, and would like to use 6-layer but haven't found a reasonably priced fab house. Is there any ...
21
votes
2answers
24k views

Mounting hole on a PCB

Here is a picture of 3 mounting holes on three different PCBs. The red one is what I prepared on Eagle CAD and used "hole" button on the left side menu , something like this: Do I need to use "...
16
votes
4answers
9k views

Feasibility of PCB edge plating?

How feasible is it to edge plate a PCB or at least a portion of one? I've seen it done but as I understand the outer edge is only cut after plating at most fab houses. Is this something that's ...
7
votes
4answers
4k views

What is the purpose of holes on edge of the PCB?

Here is a photo of one of Texas Instrument's RF EVMs. Please pay attention to edge of the PCB that has multiple tiny holes. I marked 3 of them with a red circle on the photo. What is the purpose/...
5
votes
6answers
5k views

DIY PCB Manufacture: Photoresist or Toner Transfer?

So here's what happening: I have my board layout ready to go on eagle, and am looking for a good way to produce this board at home, of a quantity of about 2 or 3, so not large scale at all. All the ...
7
votes
5answers
15k views

Correct way to define board outline?

I'm a student and am almost ready to have a PCB I designed fabricated, but I'm confused about how the board outline should be defined. Here's what I currently have: I also have a 20mil keepout line ...
7
votes
2answers
831 views

PCB Panelization tool/SW and adding test connections

I prepared 4 different PCB layouts on Eagle CAD and generated Gerber files. As I can see Eagle CAD doesn't have any option to panelization. Is there any free tool/program that can allow me to ...
6
votes
1answer
855 views

How to choose PCB manufacturing technology/factory?

I have sent some PCB designs to factories for prototyping. The price, however, varies greatly. Some ask 200 USD for a four-layer 5*10 cm PCB prototyping, while some only ask for 50 USD. I assume that ...
6
votes
1answer
593 views

How are these pcb pads made?

We want to design a pcb module that should be soldered directly onto customer pcbs (exactly like ICs ect.) I found a module which does exactly that, please see pdf. https://www.dropbox.com/s/...
2
votes
1answer
4k views

Altium Power Plane Gerber inverted

Good Day I used internal power planes for the first time (Altium), and I now want to generate fabrication outputs in the form of Gerbers. The gerber below illustrates my internal GND plane, to ...
12
votes
3answers
3k views

PCB fabrication vs PCB assembly

What is the difference between PCB fabrication and assembly? Some companies like Golden Phoenix list that based on the size of PCB, it outputs a quote. Mine was 2.1 x 1.6 inch. It outputted 29 pieces ...
9
votes
5answers
6k views

Home made PCB etching problem

I just tried to make my first PCB at home, but it did not work. I don't know what went wrong, so I'd appreciate some advice. I was using the photoresist method, so I printed my circuit on a ...
8
votes
2answers
2k views

Vias without annular ring on internal layers, non-functional pads in a via

My PCB layout package (Altium) has an option to define the full stack of a via so one may have different sized annular rings on different layers. I was wondering if it is considered "manufacturable" ...
6
votes
1answer
4k views

Are core and prepreg dielectrics interchangeable?

This is a followup to an earlier question. In my experience, PCB fab houses always default to using prepreg and foil on the surface layers. For example, on a six-layer board, the stackup would be ...
6
votes
1answer
774 views

How do PCB fabrication houses make PCBs?

I know the different ways of making PCBs at home, but I can't seem to find a lot of information on how board houses professionally make their PCBs. Is this how they do it?: http://www.youtube.com/...
5
votes
3answers
11k views

How much clearance should you include in through-hole component holes? [duplicate]

Is there a general rule as to how much clearance you should add to through-hole components' holes to allow them to fit easily? For example, if I have a component with 1mm pin diameter, what should ...
5
votes
2answers
5k views

Eagle - non solder mask defined (NSMD) pads

I am designing a PCB layout in Eagle and in the datasheet of my modul it is said that "Non solder mask defined (NSMD) type is recommended for the solder pads on the PCB". Does it mean that there will ...
4
votes
1answer
503 views

Is the dielectric layer under the top or bottom copper layers always prepreg or can it be a core?

On a PC board is the first dielectric layer looking into the board from the top or the bottom layer of copper always prepreg or can it be a core? Here "can" would mean conventional. If not then why? ...
2
votes
2answers
1k views

What constitutes a Via-in-Pad?

Would any of the via's in the picture be considered a via-in-pad? or is it only if it's dead center of the pad?
1
vote
2answers
721 views

PCB design: vcc plane and via limitations

I'm newbie in PCB design and I'm trying to achieve my first 4 layer pcb. Inner layers are gnd and vcc planes filled entirely with copper. My default trace/spacing is 0.1mm/0.1mm and drill size is 0....
14
votes
1answer
2k views

Using a via to strengthen surface mount connector on or near pad

I am trying to design a board that has a surface mount connector. I was shown a picture of an example board that has vias on the pads of the connector. I don't believe the via is for connecting to a ...
9
votes
3answers
10k views

Why do PCBs always have an even number of layers?

Looking at many online PCB fabs, when spec'ing out a board and uploading your gerbers, often you select how many Layers your board should have. Invariably, the options are always multiples of two. ...
5
votes
4answers
279 views

Methods of sliding PCB in straight line on drill press

I use a drill press like the first one in the linked answer at home for drilling my PCBs. If there was a way of sliding a PCB along a straight line left-to-right (or front-to-back) it would make ...
5
votes
3answers
1k views

Is it possible to create a double layer PCB by gluing together two single layer PCBs?

I'm really in a hurry with a university project. I need to finish the first prototype of an electronics board by the end of the week. It's a through hole board, no SMD. Having just single sided ...
4
votes
1answer
599 views

Are we still protecting pcbs with wax?

I've just replaced my smoke detector. It was manufactured in 2006 by BRK. This is an ionization-style detector. I took it apart and the track side of the circuit board is covered with a thick waxy ...
3
votes
1answer
664 views

What is the pad size required for this BGA AW H3 Chip?

I'm trying to figure out the pad size to use for my footprint according to this datasheet.The last page in the datasheet has the package dimensions. I've also posted the relevant information in a ...
3
votes
1answer
1k views

Determining the best UV exposure time

I would like to manufacture DIY PCB. I am planning to make a UV box like on this link, then I wonder how I can determine the best UV exposure time? or if I use the Sun as the UV source, how I can ...
3
votes
1answer
779 views

From what pitch should I consider ENIG finish

My design (4-layer, FR4, 1.6mm) has a couple of ICs with 0.5mm pitch pads and some LEDs with 0.4mm pitch pads, very small LEDs. Should I consider ENIG (more expensive) or will HASL do the job? I read ...
2
votes
2answers
5k views

Combining multiple EAGLE PCBs to one

I made 6 different sensors , unfortunately they are separate designs, and it cots more for production as well. I tested the prototypes and everything is working perfectly. So i dont want to change ...
2
votes
1answer
5k views

Non Plated Through Holes in Eagle

I am thinking about a project that has need for various different complicated wiring connections. I would like to make a single board that would make it as easy as possible to make arbitrary ...
1
vote
0answers
707 views

What is the black thing on the circuit [duplicate]

What is the black thing on the below circuit? Is it used to hide the IC (or other components) that is used on the circuit? What material is it?
0
votes
2answers
181 views

PCB coating for a high temperature environment

What PCB coating is good for a high temperature environment (my environment is about 30-70 C), and is available in a spray can or so that is easy to implement without need of a device/machine?
0
votes
0answers
156 views

How to properly develop a PCB everytime without taking too much photoresist off

Its been a while since I made a good PCB and I can't remember what I did to make it perfect, but after reading various resources, I have determined the following as to why most of my design was ...